The Siemens / Delphi 40A Weatherpack relay and socket we use can not be had for $1.90 in any quantity. We buy them in the thousands and know what the price schedule is from the manufacture all the way up to one million pieces. Perhaps an off-shore knock-off can be but we would not use them. Chances are you are quoting a price for an open style 30A Bosch or Hella relay and socket used for headlamps, fans, alarms etc.? A non-Weatherpack 70A relay can be purchased for less than a 40A Weatherpack relay and socket. We are cutting hairs here as the relay is only a fractional cost of the entire harness assembly.

Your posts would indicate that you have enough knowledge to do a neat job of it but not enough schooling in electronics theory to select the correct components and place them in the optimum locations. You do not recognize the WOT alternator load, alternator feed wire’s voltage drop, body ground deficiency and now this 40A breaker quote…

Using a 40A breaker would not properly protect the pump and its in-tank wiring from overheating if a problems was to develop. This is the preverbal penny in the fuse box approach. Thermal breakers should NEVER be used to protect a fuel pump circuit as they are too slow to react and their auto-reset feature is not recommeneded. There are good reasons to select the proper size fuse (not breaker) which is 20A for a Walbro pump. If your pump is drawing enough current to repeatedly blow a 20A fuse then you should not be trying to up the rating or to bypass it in order to get your car home. This could lead to a fire. One should tow their car to a location where the problem can be properly diagnosed.

Jack
Racetronix

PS. Since your car is an '83 the connectors are very easy to get as they are the Weatherpack series. Take a GOOD look at our ad for the F-LT1 harness and you will see the difference. This is one of a few reasons why the F-LT1 harness is costlier to manufacture than the F-L98 harness. I am sure many people on this board would like to see pictures of your setup once it is completed. I know I would.

 

To be honest, I don’t know of a great source for the bosch style relays. You can always find them at car audio places but they run about $15 for the relay and socket there. The local electronics supply has them for about $5-6 for the relay and socket, and you can order them from here (this is a 30A) for $1.99 (the socket is about the same from there).

The source that I have for the ‘good stuff’ is an aerospace surplus. I don’t think that I could get more then a few hundred from there at a time, but I also have no reason to believe that it would dry up either, they’ve had them for the 7 years that I’ve known about them. In quantity (more then a handful) they end up much cheaper since they will sell them by weight (and these are packaged, never used…). Same source gets me AN fittings for $3/lb ;-), but that involves some ‘picking through’ if you’re looking for something specific, they’re just thrown in big cardboard 55 gallon drums.

I guess if you’re being really cheap (and I’ve done this before just to make sure I had something while grabbing something else) you can dig them up in the junkyard, since they were OEM on a few cars (usually mounted to the firewall on FWD cars, some cars have them mounted to the fan shroud), grab them with the socket and some of the harness so you’ve got pigtails if you don’t feel like crimping new ends.

The only reason that I mentioned 40A is that that is the # that had been tossed around and that’s what I’ve used most recently for something else and I KNEW that I could get it at a good price because I had one sitting there. I realize that it’s too big for a single pump. I suspect that it would be close for twin pumps, but I’m not sure, I’d probably have to load test them or just look up their specs to know for sure.

Heh… I currently own an ’83 TA, ’87 L98 Formula and ’97WS6 TA… I’m pretty familiar with the wiring differences.

To be honest, I doubt that I’m going to be touching the fuel pumps in any of them in the near future. The reason for question about the pics of the dual pump assembly for a 3rd gen is mostly to satisfy my own curiosity. That and because sometime in the future I plan on a more serious setup in a 3rd gen.

I will probably be doing something similar soon in an ’84 LTD (basically a fox chassis mustang setup in a 4 door), but the wiring is already done. That car is running a 155L/hr pump 36Lb/hr injectors and making roughly 500hp at the crank (running over 120mph through the traps with a supercharged 302). It’s currently, surprisingly, not running out of fuel (totally flat A/F ratio all the way to redline under load), but it is getting really close. The injectors are at 100% duty cycle and there is no real leeway for tinkering, and I suspect that if we try boosting pressure (right now it’s using a factory ford turbocoupe FPR, not adjustable so we haven’t tried) or run bigger injectors to get a little leeway we’ll find where the pump will run out of pumping ability.

Jack, please don’t assume that just because I said something I believe that is the right way/don’t know any better, since more likely, it’s that way because it evolved that way from what was done to the car earlier. Hell, in this reply I’ve probably written half a dozen things that aren’t quite right but are working, and if I was starting from scratch wouldn’t be the case. But till I have a real reason to fix them they will continue working that way.

And like I said earlier, for 99% of people, yea, they probably are better off just buying the harness from you instead of cobbling something together… Believe me, being a 3rd gen fan it seems that you always run across something ugly that a previous owner cobbled, that desperately needs fixing. You should see the VSS and some of the ECM wiring in my ’87, which was supposedly done by the dealer after 4 warranty claims…

FWIW, I am familiar with your setup. In the last 2 years I’ve installed one on a TTA, and chased problems on one in a typhoon (turned out to be the pump) and a GN (turned out to be a bad relay).

 

WS6 TA

You might as well quick aruging with the wall!! Remember he is above everyone and knows everything



I can't believe he is saying what you can and can't buy parts for...

 

Exactly what I thought. This relay is an open style relay which can be had for around $2.00 and the socket for around $1.00. It is not a Weatherpack type relay which is used in our harnesses. A Weatherpack relay is sealed against the elements with silicon seals on the relay socket for the body and wire entry points. This is why our relays can be mounted under the car where they are directly exposed to water spray etc. without being effected. Moisture will not set in and rot the contacts over time. Using an open style relay is a liability especially in parts of the continent were there is humidity even if it is mounted in an area where it is not exposed to the elements.

You should not use a 40A breaker for both pumps. Each pump should be fused at 20 amps individually.

You have to remember that some people reading this forum use the information posted to take the D-I-Y approach so it is important that the information posted is accurate. We receive many emails from people asking tech questions to help fix problems because of some inaccurate D-I-Y posting they were trying to follow on a forum. The details are everything!

My intention for discussing this topic is to help educate the forum readers on the distinct detailed differences between certain components, proper wiring procedures and component selection. I never claimed to be an expert at everything however I am in this area. People are free to wire their cars as they please. Hopefully at the end of the day the information I post will help them make a better job of it.

Jack
Racetronix

 

Please contact sales@racetronix.com or Agostino Racing Engines for current pricing and availability for the DP system.

Thank you,
Jack
Racetronix

 

Right, exactly. What I’m saying is that I CAN NOT get the normal bosch style relay ($3-6 depending on if I’m willing to wait for mail order) as cheap as I can get the weatherpack relay and socket ($2).

I wouldn’t use the bosch style relay under the car… you’re just asking for problems there, unless you mount everything in a relatively weatherproof box. Same deal with the relay that they use in the hotwire kits (which can be had fairly easily at any electronics store, even radioshack).

Right.

At which point those of us that are **** retentive pull the carpeting in our cars, pull the factory wiring and bulkhead connector and run the whole mess inside the car. If the battery is still in the front it’s usually time to run a larger positive (with appropriate fuseable link or large fuse) to the back of the car and setup a distribution block/fuse block for things like the fp, bottle heater, water pump for air/water intercooler…. Or if the battery is in the back, extend the old factory wires to there, mount the relay, fuses… under the wheel well trim panel and wire the high amp side of the thing straight to the alternator wire running back to your cut off switch.

 

Which company uses non-Weatherpack relays in their 'Hotwire' kits? Are you referring to Painless product?

Jack
Racetronix

 

don't know who sold it originally, but I've seen them on a few GN's that have had the kit installed for a while (at least 5 years). They look like MECI Part Number: 480-0051 (not sure that they're the exact relay, but they do look like that). If it really makes a difference I could find out, I've got a friend that has one...